Normally one of the big brands is at Target for $1.99. Costco sells a case of 12 for $24. Same thing, so I normally buy about 6 cans at a time at Target. I don't want to buy too many at once near the change in season due to the High Altitude vs. Low Altitude thing.

Two bucks is about the going price for a tube of Penn or Wilson Championship , perhaps $2.50 for a ball with a better felt covering like the Wilson US Open or Pro Penn. If you want balls for practice or a ball machine, I would suggest pressure-less balls you can buy in bulk like the Tretorn Micro-X. They have a consistent bounce and last a long time.